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2014-07-19Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "The locking department delivers: - A rather large and intrusive bundle of fixes to address serious performance regressions introduced by the new rwsem / mcs technology. Simpler solutions have been discussed, but they would have been ugly bandaids with more risk than doing the right thing. - Make the rwsem spin on owner technology opt-in for architectures and enable it only on the known to work ones. - A few fixes to the lockdep userspace library" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER locking/mutex: Disable optimistic spinning on some architectures locking/rwsem: Reduce the size of struct rw_semaphore locking/rwsem: Rename 'activity' to 'count' locking/spinlocks/mcs: Micro-optimize osq_unlock() locking/spinlocks/mcs: Introduce and use init macro and function for osq locks locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node() locking/rwsem: Allow conservative optimistic spinning when readers have lock tools/liblockdep: Account for bitfield changes in lockdeps lock_acquire tools/liblockdep: Remove debug print left over from development tools/liblockdep: Fix comparison of a boolean value with a value of 2
2014-07-19Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "A couple of key fixes and a few less critical ones. The main ones are: - add a .bss section to the PE/COFF headers when building with EFI stub - invoke the correct paravirt magic when building the espfix page tables Unfortunately both of these areas also have at least one additional fix each still in thie pipeline, but which are not yet ready to push" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Remove unused variable "polling" x86/espfix/xen: Fix allocation of pages for paravirt page tables x86/efi: Include a .bss section within the PE/COFF headers efi: fdt: Do not report an error during boot if UEFI is not available efi/arm64: efistub: remove local copy of linux_banner
2014-07-16Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A cpufreq lockup fix and a compiler warning fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix compiler warnings x86, tsc: Fix cpufreq lockup
2014-07-16Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Tooling fixes and an Intel PMU driver fixlet" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do not allow optimized switch for non-cloned events perf/x86/intel: ignore CondChgd bit to avoid false NMI handling perf symbols: Get kernel start address by symbol name perf tools: Fix segfault in cumulative.callchain report
2014-07-16locking/mutex: Disable optimistic spinning on some architecturesPeter Zijlstra
The optimistic spin code assumes regular stores and cmpxchg() play nice; this is found to not be true for at least: parisc, sparc32, tile32, metag-lock1, arc-!llsc and hexagon. There is further wreckage, but this in particular seemed easy to trigger, so blacklist this. Opt in for known good archs. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Jason Low <jason.low2@hp.com> Cc: Waiman Long <waiman.long@hp.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: John David Anglin <dave.anglin@bell.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: stable@vger.kernel.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16x86: Remove unused variable "polling"Paul Bolle
Compile tested. "polling" is unused since commit f80c5b39b80a ("sched/idle, x86: Switch from TS_POLLING to TIF_POLLING_NRFLAG"). Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jkosina@suse.cz> Link: http://lkml.kernel.org/r/1404138749.2978.6.camel@x41 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-14x86/espfix/xen: Fix allocation of pages for paravirt page tablesBoris Ostrovsky
init_espfix_ap() is currently off by one level when informing hypervisor that allocated pages will be used for ministacks' page tables. The most immediate effect of this on a PV guest is that if 'stack_page = __get_free_page()' returns a non-zeroed-out page the hypervisor will refuse to use it for a page table (which it shouldn't be anyway). This will result in warnings by both Xen and Linux. More importantly, a subsequent write to that page (again, by a PV guest) is likely to result in fatal page fault. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: http://lkml.kernel.org/r/1404926298-5565-1-git-send-email-boris.ostrovsky@oracle.com Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org>
2014-07-14Merge tag 'efi-urgent' into x86/urgentH. Peter Anvin
* Remove a duplicate copy of linux_banner from the arm64 EFI stub which, apart from reducing code duplication also stops the arm64 stub being rebuilt every time make is invoked - Ard Biesheuvel * Fix the EFI fdt code to not report a boot error if UEFI is unavailable since booting without UEFI parameters is a valid use case for non-UEFI platforms - Catalin Marinas * Include a .bss section in the EFI boot stub PE/COFF headers to fix a memory corruption bug - Michael Brown Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-12Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "A couple of further build fixes for the VDSO code. This is turning into a bit of a headache, and Andy has already come up with a more ultimate cleanup, but most likely that is 3.17 material" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-32, vdso: Fix vDSO build error due to missing align_vdso_addr() x86-64, vdso: Fix vDSO build breakage due to empty .rela.dyn
2014-07-10x86-32, vdso: Fix vDSO build error due to missing align_vdso_addr()Jan Beulich
Relying on static functions used just once to get inlined (and subsequently have dead code paths eliminated) is wrong: Compilers are free to decide whether they do this, regardless of optimization level. With this not happening for vdso_addr() (observed with gcc 4.1.x), an unresolved reference to align_vdso_addr() causes the build to fail. [ hpa: vdso_addr() is never actually used on x86-32, as calculate_addr in map_vdso() is always false. It ought to be possible to clean this up further, but this fixes the immediate problem. ] Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/53B5863B02000078000204D5@mail.emea.novell.com Acked-by: Andy Lutomirski <luto@amacapital.net> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-10x86-64, vdso: Fix vDSO build breakage due to empty .rela.dynJan Beulich
Certain ld versions (observed with 2.20.0) put an empty .rela.dyn section into shared object files, breaking the assumption on the number of sections to be copied to the final output. Simply discard any empty SHT_REL and SHT_RELA sections to address this. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/53B5861E02000078000204D1@mail.emea.novell.com Acked-by: Andy Lutomirski <luto@amacapital.net> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds
Pull crypto fixes from Herbert Xu: "This push fixes an error in sha512_ssse3 that leads to incorrect output as well as a memory leak in caam_jr when the module is unloaded" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: caam - fix memleak in caam_jr module crypto: sha512_ssse3 - fix byte count to bit count conversion
2014-07-10x86/efi: Include a .bss section within the PE/COFF headersMichael Brown
The PE/COFF headers currently describe only the initialised-data portions of the image, and result in no space being allocated for the uninitialised-data portions. Consequently, the EFI boot stub will end up overwriting unexpected areas of memory, with unpredictable results. Fix by including a .bss section in the PE/COFF headers (functionally equivalent to the init_size field in the bzImage header). Signed-off-by: Michael Brown <mbrown@fensystems.co.uk> Cc: Thomas Bächler <thomas@archlinux.org> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-04ptrace,x86: force IRET path after a ptrace_stop()Tejun Heo
The 'sysret' fastpath does not correctly restore even all regular registers, much less any segment registers or reflags values. That is very much part of why it's faster than 'iret'. Normally that isn't a problem, because the normal ptrace() interface catches the process using the signal handler infrastructure, which always returns with an iret. However, some paths can get caught using ptrace_event() instead of the signal path, and for those we need to make sure that we aren't going to return to user space using 'sysret'. Otherwise the modifications that may have been done to the register set by the tracer wouldn't necessarily take effect. Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from arch_ptrace_stop_needed() which is invoked from ptrace_stop(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-02perf/x86/intel: ignore CondChgd bit to avoid false NMI handlingHATAYAMA Daisuke
Currently, any NMI is falsely handled by a NMI handler of NMI watchdog if CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR is set. For example, we use external NMI to make system panic to get crash dump, but in this case, the external NMI is falsely handled do to the issue. This commit deals with the issue simply by ignoring CondChgd bit. Here is explanation in detail. On x86 NMI watchdog uses performance monitoring feature to periodically signal NMI each time performance counter gets overflowed. intel_pmu_handle_irq() is called as a NMI_LOCAL handler from a NMI handler of NMI watchdog, perf_event_nmi_handler(). It identifies an owner of a given NMI by looking at overflow status bits in MSR_CORE_PERF_GLOBAL_STATUS MSR. If some of the bits are set, then it handles the given NMI as its own NMI. The problem is that the intel_pmu_handle_irq() doesn't distinguish CondChgd bit from other bits. Unlike the other status bits, CondChgd bit doesn't represent overflow status for performance counters. Thus, CondChgd bit cannot be thought of as a mark indicating a given NMI is NMI watchdog's. As a result, if CondChgd bit is set, any NMI is falsely handled by the NMI handler of NMI watchdog. Also, if type of the falsely handled NMI is either NMI_UNKNOWN, NMI_SERR or NMI_IO_CHECK, the corresponding action is never performed until CondChgd bit is cleared. I noticed this behavior on systems with Ivy Bridge processors: Intel Xeon CPU E5-2630 v2 and Intel Xeon CPU E7-8890 v2. On both systems, CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR has already been set in the beginning at boot. Then the CondChgd bit is immediately cleared by next wrmsr to MSR_CORE_PERF_GLOBAL_CTRL MSR and appears to remain 0. On the other hand, on older processors such as Nehalem, Xeon E7540, CondChgd bit is not set in the beginning at boot. I'm not sure about exact behavior of CondChgd bit, in particular when this bit is set. Although I read Intel System Programmer's Manual to figure out that, the descriptions I found are: In 18.9.1: "The MSR_PERF_GLOBAL_STATUS MSR also provides a ¡sticky bit¢ to indicate changes to the state of performancmonitoring hardware" In Table 35-2 IA-32 Architectural MSRs 63 CondChg: status bits of this register has changed. These are different from the bahviour I see on the actual system as I explained above. At least, I think ignoring CondChgd bit should be enough for NMI watchdog perspective. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140625.103503.409316067.d.hatayama@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-02x86, tsc: Fix cpufreq lockupPeter Zijlstra
Mauro reported that his AMD X2 using the powernow-k8 cpufreq driver locked up when doing cpu hotplug. Because we called set_cyc2ns_scale() from the time_cpufreq_notifier() unconditionally, it gets called multiple times for each freq change, instead of only the once, when the tsc_khz value actually changes. Because it gets called more than once, we run out of cyc2ns data slots and stall, waiting for a free one, but because we're half way offline, there's no consumers to free slots. By placing the call inside the condition that actually changes tsc_khz we avoid superfluous calls and avoid the problem. Reported-by: Mauro <registosites@hotmail.com> Tested-by: Mauro <registosites@hotmail.com> Fixes: 20d1c86a5776 ("sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs") Cc: <stable@vger.kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Bin Gao <bin.gao@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "A bunch of one-liners (except the s390 one). The two more serious bugs ("KVM: SVM: Fix CPL export via SS.DPL" and "KVM: s390: add sie.h uapi header file to Kbuild and remove header dependency") were introduced in the 3.16 merge window" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: SVM: Fix CPL export via SS.DPL KVM: s390: add sie.h uapi header file to Kbuild and remove header dependency MIPS: KVM: Fix memory leak on VCPU KVM: x86: preserve the high 32-bits of the PAT register kvm: fix wrong address when writing Hyper-V tsc page KVM: x86: Increase the number of fixed MTRR regs to 10
2014-06-30Merge commit '33b458d276bb' into kvm-masterPaolo Bonzini
2014-06-30KVM: SVM: Fix CPL export via SS.DPLJan Kiszka
We import the CPL via SS.DPL since ae9fedc793. However, we fail to export it this way so far. This caused spurious guest crashes, e.g. of Linux when accessing the vmport from guest user space which triggered register saving/restoring to/from host user space. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-28Merge branch 'x86/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "A pile of fixes related to the VDSO, EFI and 32-bit badsys handling. It turns out that removing the section headers from the VDSO breaks gdb, so this puts back most of them. A very simple typo broke rt_sigreturn on some versions of glibc, with obviously disastrous results. The rest is pretty much fixes for the corresponding fallout. The EFI fixes fixes an arithmetic overflow on 32-bit systems and quiets some build warnings. Finally, when invoking an invalid system call number on x86-32, we bypass a bunch of handling, which can make the audit code oops" * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi-pstore: Fix an overflow on 32-bit builds x86/vdso: Error out in vdso2c if DT_RELA is present x86/vdso: Move DISABLE_BRANCH_PROFILING into the vdso makefile x86_32, signal: Fix vdso rt_sigreturn x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508) x86/vdso: Create .build-id links for unstripped vdso files x86/vdso: Remove some redundant in-memory section headers x86/vdso: Improve the fake section headers x86/vdso2c: Use better macros for ELF bitness x86/vdso: Discard the __bug_table section efi: Fix compiler warnings (unused, const, type)
2014-06-25crypto: sha512_ssse3 - fix byte count to bit count conversionJussi Kivilinna
Byte-to-bit-count computation is only partly converted to big-endian and is mixing in CPU-endian values. Problem was noticed by sparce with warning: CHECK arch/x86/crypto/sha512_ssse3_glue.c arch/x86/crypto/sha512_ssse3_glue.c:144:19: warning: restricted __be64 degrades to integer arch/x86/crypto/sha512_ssse3_glue.c:144:17: warning: incorrect type in assignment (different base types) arch/x86/crypto/sha512_ssse3_glue.c:144:17: expected restricted __be64 <noident> arch/x86/crypto/sha512_ssse3_glue.c:144:17: got unsigned long long Cc: <stable@vger.kernel.org> Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi> Acked-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-06-24x86/vdso: Error out in vdso2c if DT_RELA is presentAndy Lutomirski
vdso2c was checking for various types of relocations to detect when the vdso had undefined symbols or was otherwise dependent on relocation at load time. Undefined symbols in the vdso would fail if accessed at runtime, and certain implementation errors (e.g. branch profiling or incorrect symbol visibilities) could result in data access through the GOT that requires relocations. This could be as simple as: extern char foo; return foo; Without some kind of visibility control, the compiler would assume that foo could be interposed at load time and would generate a relocation. x86-64 and x32 (as opposed to i386) use explicit-addent (RELA) instead of implicit-addent (REL) relocations for data access, and vdso2c forgot to detect those. Whether these bad relocations would actually fail at runtime depends on what the linker sticks in the unrelocated references. Nonetheless, these relocations have no business existing in the vDSO and should be fixed rather than silently ignored. This error could trigger on some configurations due to branch profiling. The previous patch fixed that. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/74ef0c00b4d2a3b573e00a4113874e62f772e348.1403642755.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-24x86/vdso: Move DISABLE_BRANCH_PROFILING into the vdso makefileAndy Lutomirski
DISABLE_BRANCH_PROFILING turns off branch profiling (i.e. a redefinition of 'if'). Branch profiling depends on a bunch of kernel-internal symbols and generates extra output sections, none of which are useful or functional in the vDSO. It's currently turned off for vclock_gettime.c, but vgetcpu.c also triggers branch profiling, so just turn it off in the makefile. This fixes the build on some configurations: the vdso could contain undefined symbols, and the fake section table overflowed due to ftrace's added sections. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/bf1ec29e03b2bbc081f6dcaefa64db1c3a83fb21.1403642755.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-23nmi: provide the option to issue an NMI back trace to every cpu but currentAaron Tomlin
Sometimes it is preferred not to use the trigger_all_cpu_backtrace() routine when one wants to avoid capturing a back trace for current. For instance if one was previously captured recently. This patch provides a new routine namely trigger_allbutself_cpu_backtrace() which offers the flexibility to issue an NMI to every cpu but current and capture a back trace accordingly. Patch x86 and sparc to support new routine. [dzickus@redhat.com: add stub in #else clause] [dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion] [sfr@canb.auug.org.au: undo C99ism] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23x86_32, signal: Fix vdso rt_sigreturnAndy Lutomirski
This commit: commit 6f121e548f83674ab4920a4e60afb58d4f61b829 Author: Andy Lutomirski <luto@amacapital.net> Date: Mon May 5 12:19:34 2014 -0700 x86, vdso: Reimplement vdso.so preparation in build-time C Contained this obvious typo: - restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); + restorer = current->mm->context.vdso + + selected_vdso32->sym___kernel_sigreturn; Note the missing 'rt_' in the new code. Fix it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/1eb40ad923acde2e18357ef2832867432e70ac42.1403361010.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-23x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)Andy Lutomirski
The bad syscall nr paths are their own incomprehensible route through the entry control flow. Rearrange them to work just like syscalls that return -ENOSYS. This fixes an OOPS in the audit code when fast-path auditing is enabled and sysenter gets a bad syscall nr (CVE-2014-4508). This has probably been broken since Linux 2.6.27: af0575bba0 i386 syscall audit fast-path Cc: stable@vger.kernel.org Cc: Roland McGrath <roland@redhat.com> Reported-by: Toralf Förster <toralf.foerster@gmx.de> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/e09c499eade6fc321266dd6b54da7beb28d6991c.1403558229.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-21Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This is larger than usual: the main reason are the ARM symbol lookup speedups that came in late and were hard to resist. There's also a kprobes fix and various tooling fixes, plus the minimal re-enablement of the mmap2 support interface" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/kprobes: Fix build errors and blacklist context_track_user perf tests: Add test for closing dso objects on EMFILE error perf tests: Add test for caching dso file descriptors perf tests: Allow reuse of test_file function perf tests: Spawn child for each test perf tools: Add dso__data_* interface descriptons perf tools: Allow to close dso fd in case of open failure perf tools: Add file size check and factor dso__data_read_offset perf tools: Cache dso data file descriptor perf tools: Add global count of opened dso objects perf tools: Add global list of opened dso objects perf tools: Add data_fd into dso object perf tools: Separate dso data related variables perf tools: Cache register accesses for unwind processing perf record: Fix to honor user freq/interval properly perf timechart: Reflow documentation perf probe: Improve error messages in --line option perf probe: Improve an error message of perf probe --vars mode perf probe: Show error code and description in verbose mode perf probe: Improve error message for unknown member of data structure ...
2014-06-20x86/vdso: Create .build-id links for unstripped vdso filesAndy Lutomirski
With this change, doing 'make vdso_install' and telling gdb: set debug-file-directory /lib/modules/KVER/vdso will enable vdso debugging with symbols. This is useful for testing, but kernel RPM builds will probably want to manually delete these symlinks or otherwise do something sensible when they strip the vdso/*.so files. If ld does not support --build-id, then the symlinks will not be created. Note that kernel packagers that use vdso_install may need to adjust their packaging scripts to accomdate this change. For example, Fedora's scripts create build-id symlinks themselves in a different location, so the spec should probably be updated to remove the symlinks created by make vdso_install. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/a424b189ce3ced85fe1e82d032a20e765e0fe0d3.1403291930.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-20Merge tag 'pm+acpi-3.16-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "These are fixes mostly (ia64 regression related to the ACPI enumeration of devices, cpufreq regressions, fix for I2C controllers included in Intel SoCs, mvebu cpuidle driver fix related to sysfs) plus additional kernel command line arguments from Kees to make it possible to build kernel images with hibernation and the kernel address space randomization included simultaneously, a new ACPI battery driver quirk for a system with a broken BIOS and a couple of ACPI core cleanups. Specifics: - Fix for an ia64 regression introduced during the 3.11 cycle by a commit that modified the hardware initialization ordering and made device discovery fail on some systems. - Fix for a build problem on systems where the cpufreq-cpu0 driver is built-in and the cpu-thermal driver is modular from Arnd Bergmann. - Fix for a recently introduced computational mistake in the intel_pstate driver that leads to excessive rounding errors from Doug Smythies. - Fix for a failure code path in cpufreq_update_policy() that fails to unlock the locks acquired previously from Aaron Plattner. - Fix for the cpuidle mvebu driver to use shorter state names which will prevent the sysfs interface from returning mangled strings. From Gregory Clement. - ACPI LPSS driver fix to make sure that the I2C controllers included in BayTrail SoCs are not held in the reset state while they are being probed from Mika Westerberg. - New kernel command line arguments making it possible to build kernel images with hibernation and kASLR included at the same time and to select which of them will be used via the command line (they are still functionally mutually exclusive, though). From Kees Cook. - ACPI battery driver quirk for Acer Aspire V5-573G that fails to send battery status change notifications timely from Alexander Mezin. - Two ACPI core cleanups from Christoph Jaeger and Fabian Frederick" * tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: mvebu: Fix the name of the states cpufreq: unlock when failing cpufreq_update_policy() intel_pstate: Correct rounding in busy calculation ACPI: use kstrto*() instead of simple_strto*() ACPI / processor replace __attribute__((packed)) by __packed ACPI / battery: add quirk for Acer Aspire V5-573G ACPI / battery: use callback for setting up quirks ACPI / LPSS: Take I2C host controllers out of reset x86, kaslr: boot-time selectable with hibernation PM / hibernate: introduce "nohibernate" boot parameter cpufreq: cpufreq-cpu0: fix CPU_THERMAL dependency ACPI / ia64 / sba_iommu: Restore the working initialization ordering
2014-06-19x86/vdso: Remove some redundant in-memory section headersAndy Lutomirski
.data doesn't need to be separate from .rodata: they're both readonly. .altinstructions and .altinstr_replacement aren't needed by anything except vdso2c; strip them from the final image. While we're at it, rather than aligning the actual executable text, just shove some unused-at-runtime data in between real data and text. My vdso image is still above 4k, but I'm disinclined to try to trim it harder for 3.16. For future trimming, I suspect that these sections could be moved to later in the file and dropped from the in-memory image: .gnu.version and .gnu.version_d (this may lose versions in gdb) .eh_frame (should be harmless) .eh_frame_hdr (I'm not really sure) .hash (AFAIK nothing needs this section header) Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2e96d0c49016ea6d026a614ae645e93edd325961.1403129369.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-19x86/vdso: Improve the fake section headersAndy Lutomirski
Fully stripping the vDSO has other unfortunate side effects: - binutils is unable to find ELF notes without a SHT_NOTE section. - Even elfutils has trouble: it can find ELF notes without a section table at all, but if a section table is present, it won't look for PT_NOTE. - gdb wants section names to match between stripped DSOs and their symbols; otherwise it will corrupt symbol addresses. We're also breaking the rules: section 0 is supposed to be SHT_NULL. Fix these problems by building a better fake section table. While we're at it, we might as well let buggy Go versions keep working well by giving the SHT_DYNSYM entry the correct size. This is a bit unfortunate: it adds quite a bit of size to the vdso image. If/when binutils improves and the improved versions become widespread, it would be worth considering dropping most of this. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/0e546a5eeaafdf1840e6ee654a55c1e727c26663.1403129369.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-19x86/vdso2c: Use better macros for ELF bitnessAndy Lutomirski
Rather than using a separate macro for each replacement, use generic macros. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/d953cd2e70ceee1400985d091188cdd65fba2f05.1403129369.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-19x86/vdso: Discard the __bug_table sectionAndy Lutomirski
It serves no purpose in user code. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2a5bebff42defd8a5e81d96f7dc00f21143c80e8.1403129369.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-19Merge tag 'stable/for-linus-3.16-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen fixes from David Vrabel: "Xen regression and PVH fixes for 3.16-rc1 - fix dom0 PVH memory setup on latest unstable Xen releases - fix 64-bit x86 PV guest boot failure on Xen 3.1 and earlier - fix resume regression on non-PV (auto-translated physmap) guests" * tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/grant-table: fix suspend for non-PV guests x86/xen: no need to explicitly register an NMI callback Revert "xen/pvh: Update E820 to work with PVH (v2)" x86/xen: fix memory setup for PVH dom0
2014-06-19KVM: x86: preserve the high 32-bits of the PAT registerPaolo Bonzini
KVM does not really do much with the PAT, so this went unnoticed for a long time. It is exposed however if you try to do rdmsr on the PAT register. Reported-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19kvm: fix wrong address when writing Hyper-V tsc pageXiaoming Gao
When kvm_write_guest writes the tsc_ref structure to the guest, or it will lead the low HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT bits of the TSC page address must be cleared, or the guest can see a non-zero sequence number. Otherwise Windows guests would not be able to get a correct clocksource (QueryPerformanceCounter will always return 0) which causes serious chaos. Signed-off-by: Xiaoming Gao <newtongao@tencnet.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19KVM: x86: Increase the number of fixed MTRR regs to 10Nadav Amit
Recent Intel CPUs have 10 variable range MTRRs. Since operating systems sometime make assumptions on CPUs while they ignore capability MSRs, it is better for KVM to be consistent with recent CPUs. Reporting more MTRRs than actually supported has no functional implications. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-18x86/xen: no need to explicitly register an NMI callbackDavid Vrabel
Remove xen_enable_nmi() to fix a 64-bit guest crash when registering the NMI callback on Xen 3.1 and earlier. It's not needed since the NMI callback is set by a set_trap_table hypercall (in xen_load_idt() or xen_write_idt_entry()). It's also broken since it only set the current VCPU's callback. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
2014-06-16x86, kaslr: boot-time selectable with hibernationKees Cook
Changes kASLR from being compile-time selectable (blocked by CONFIG_HIBERNATION), to being boot-time selectable (with hibernation available by default) via the "kaslr" kernel command line. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-14Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso fixes from Peter Anvin: "Fixes for x86/vdso. One is a simple build fix for bigendian hosts, one is to make "make vdso_install" work again, and the rest is about working around a bug in Google's Go language -- two are documentation patches that improves the sample code that the Go coders took, modified, and broke; the other two implements a workaround that keeps existing Go binaries from segfaulting at least" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Fix vdso_install x86/vdso: Hack to keep 64-bit Go programs working x86/vdso: Add PUT_LE to store little-endian values x86/vdso/doc: Make vDSO examples more portable x86/vdso/doc: Rename vdso_test.c to vdso_standalone_test_x86.c x86, vdso: Remove one final use of htole16()
2014-06-14x86/kprobes: Fix build errors and blacklist context_track_userMasami Hiramatsu
This essentially reverts commit: ecd50f714c42 ("kprobes, x86: Call exception_enter after kprobes handled") since it causes build errors with CONFIG_CONTEXT_TRACKING and that has been made from misunderstandings; context_track_user_*() don't involve much in interrupt context, it just returns if in_interrupt() is true. Instead of changing the do_debug/int3(), this just adds context_track_user_*() to kprobes blacklist, since those are still can be called right before kprobes handles int3 and debug exceptions, and probing those will cause an infinite loop. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20140614064711.7865.45957.stgit@kbuild-fedora.novalocal Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-13x86/vdso: Fix vdso_installAndy Lutomirski
"make vdso_install" installs unstripped versions of the vdso objects for the benefit of the debugger. This was broken by checkin: 6f121e548f83 x86, vdso: Reimplement vdso.so preparation in build-time C The filenames are different now, so update the Makefile to cope. This still installs the 64-bit vdso as vdso64.so. We believe this will be okay, as the only known user is a patched gdb which is known to use build-ids, but if it turns out to be a problem we may have to add a link. Inspired by a patch from Sam Ravnborg. Acked-by: Sam Ravnborg <sam@ravnborg.org> Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Tested-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/b10299edd8ba98d17e07dafcd895b8ecf4d99eff.1402586707.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-06-13Merge branch 'x86-irq-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq fixes from Ingo Molnar: "Two changes: a cpu-hotplug/irq race fix, plus a HyperV related fix" * 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Fix fixup_irqs() error handling x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately
2014-06-13Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...
2014-06-13x86/vdso: Hack to keep 64-bit Go programs workingAndy Lutomirski
The Go runtime has a buggy vDSO parser that currently segfaults. This writes an empty SHT_DYNSYM entry that causes Go's runtime to malfunction by thinking that the vDSO is empty rather than malfunctioning by running off the end and segfaulting. This affects x86-64 only as far as we know, so we do not need this for the i386 and x32 vdsos. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/d10618176c4bd39b457a5e85c497295c90cab1bc.1402620737.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-06-13x86/vdso: Add PUT_LE to store little-endian valuesAndy Lutomirski
Add PUT_LE() by analogy with GET_LE() to write littleendian values in addition to reading them. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/3d9b27e92745b27b6fda1b9a98f70dc9c1246c7a.1402620737.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-06-13Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more locking changes from Ingo Molnar: "This is the second round of locking tree updates for v3.16, offering large system scalability improvements: - optimistic spinning for rwsems, from Davidlohr Bueso. - 'qrwlocks' core code and x86 enablement, from Waiman Long and PeterZ" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, locking/rwlocks: Enable qrwlocks on x86 locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks locking/mutexes: Documentation update/rewrite locking/rwsem: Fix checkpatch.pl warnings locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK locking/rwsem: Support optimistic spinning
2014-06-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov. 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J Benniston. 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn Mork. 4) BPF now has a "random" opcode, from Chema Gonzalez. 5) Add more BPF documentation and improve test framework, from Daniel Borkmann. 6) Support TCP fastopen over ipv6, from Daniel Lee. 7) Add software TSO helper functions and use them to support software TSO in mvneta and mv643xx_eth drivers. From Ezequiel Garcia. 8) Support software TSO in fec driver too, from Nimrod Andy. 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli. 10) Handle broadcasts more gracefully over macvlan when there are large numbers of interfaces configured, from Herbert Xu. 11) Allow more control over fwmark used for non-socket based responses, from Lorenzo Colitti. 12) Do TCP congestion window limiting based upon measurements, from Neal Cardwell. 13) Support busy polling in SCTP, from Neal Horman. 14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru. 15) Bridge promisc mode handling improvements from Vlad Yasevich. 16) Don't use inetpeer entries to implement ID generation any more, it performs poorly, from Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits) rtnetlink: fix userspace API breakage for iproute2 < v3.9.0 tcp: fixing TLP's FIN recovery net: fec: Add software TSO support net: fec: Add Scatter/gather support net: fec: Increase buffer descriptor entry number net: fec: Factorize feature setting net: fec: Enable IP header hardware checksum net: fec: Factorize the .xmit transmit function bridge: fix compile error when compiling without IPv6 support bridge: fix smatch warning / potential null pointer dereference via-rhine: fix full-duplex with autoneg disable bnx2x: Enlarge the dorq threshold for VFs bnx2x: Check for UNDI in uncommon branch bnx2x: Fix 1G-baseT link bnx2x: Fix link for KR with swapped polarity lane sctp: Fix sk_ack_backlog wrap-around problem net/core: Add VF link state control policy net/fsl: xgmac_mdio is dependent on OF_MDIO net/fsl: Make xgmac_mdio read error message useful net_sched: drr: warn when qdisc is not work conserving ...
2014-06-12Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm updates from Dave Airlie: "This is the main drm merge window pull request, changes all over the place, mostly normal levels of churn. Highlights: Core drm: More cleanups, fix race on connector/encoder naming, docs updates, object locking rework in prep for atomic modeset i915: mipi DSI support, valleyview power fixes, cursor size fixes, execlist refactoring, vblank improvements, userptr support, OOM handling improvements radeon: GPUVM tuning and large page size support, gart fixes, deep color HDMI support, HDMI audio cleanups nouveau: - displayport rework should fix lots of issues - initial gk20a support - gk110b support - gk208 fixes exynos: probe order fixes, HDMI changes, IPP consolidation msm: debugfs updates, misc fixes ast: ast2400 support, sync with UMS driver tegra: cleanups, hdmi + hw cursor for Tegra 124. panel: fixes existing panels add some new ones. ipuv3: moved from staging to drivers/gpu" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (761 commits) drm/nouveau/disp/dp: fix tmds passthrough on dp connector drm/nouveau/dp: probe dpcd to determine connectedness drm/nv50-: trigger update after all connectors disabled drm/nv50-: prepare for attaching a SOR to multiple heads drm/gf119-/disp: fix debug output on update failure drm/nouveau/disp/dp: make use of postcursor when its available drm/g94-/disp/dp: take max pullup value across all lanes drm/nouveau/bios/dp: parse lane postcursor data drm/nouveau/dp: fix support for dpms drm/nouveau: register a drm_dp_aux channel for each dp connector drm/g94-/disp: add method to power-off dp lanes drm/nouveau/disp/dp: maintain link in response to hpd signal drm/g94-/disp: bash and wait for something after changing lane power regs drm/nouveau/disp/dp: split link config/power into two steps drm/nv50/disp: train PIOR-attached DP from second supervisor drm/nouveau/disp/dp: make use of existing output data for link training drm/gf119/disp: start removing direct vbios parsing from supervisor drm/nv50/disp: start removing direct vbios parsing from supervisor drm/nouveau/disp/dp: maintain receiver caps in response to hpd signal drm/nouveau/disp/dp: create subclass for dp outputs ...
2014-06-11net: filter: cleanup A/X name usageAlexei Starovoitov
The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>